Accelerating ferroic ageing dynamics upon cooling

Once a structural glass is formed, its relaxation time will increase exponentially with decreasing temperature. Thus, the glass has little chance of transforming into a crystal upon further cooling to zero Kelvin. However, a spontaneous transition upon cooling from amorphous to long-range ordered ferroic states has been observed experimentally in ferroelastic, ferroelectric and ferromagnetic materials. The origin for this obvious discrepancy is discussed here conceptually. We present a combined theoretical and numerical study of this phenomenon and show that the diffusive and displacive atomic processes that take place in structural glass and amorphous ferroics, respectively, lead to markedly different temperature-dependent relaxation behaviors, one being ‘colder is slower’ and the other being ‘colder is faster’.National Basic Research Program of China (2012CB619402)National Basic Research Program of China (2014CB644003)National Key Basic Research Program of China (51671156)National Basic Research Program of China 111 Project (B06025)National Science Foundation (U.S.). Division of Materials Research (DMR-1410322)National Science Foundation (U.S.). Division of Materials Research (DMR-1410636

Stress-driven crystallization via shear-diffusion transformations in a metallic glass at very low temperatures

At elevated temperatures, glasses crystallize via thermally activated diffusion. However, metallic glasses can also undergo deformation-induced crystallization at very low temperatures. Here we demonstrate the crystallization of Al[subscript 50]Fe[subscript 50] metallic glasses under cyclic deformation at 50 K using molecular dynamics simulations and reveal the underlying atomic-scale processes. We demonstrate that stress-driven nonaffine atomic rearrangements, or shear diffusion transformation (SDT) events, lead to successive metabasin-to-metabasin transitions and long-range ordering. We also illustrate that the nucleation and growth of the crystal proceed via collective attachment of ordered clusters, advancing the amorphous/crystal interface in an intermittent manner. The cooperative nature of the steplike crystallization is attributed to the large activation volume of Eshelby transformations which generate as a by-product nonaffine diffusive atomic displacements that accumulate over loading cycles. The dual nature of shear (affine) and diffusion (nonaffine) in low-temperature stress-driven SDT events thus unifies inelasticity with crystallization.National Basic Research Program of China (973 Program) (Grant 2012CB619402)National Basic Research Program of China (111 Program) (Grant B06025)National Science Foundation (U.S.) (Grant DMR-1120901)National Science Foundation (U.S.) (Grant DMR-1410636

LooPIN: A PinFi protocol for decentralized computing

Networked computing power is a critical utility in the era of artificial intelligence. This paper presents a novel Physical Infrastructure Finance (PinFi) protocol designed to facilitate the distribution of computing power within networks in a decentralized manner. Addressing the core challenges of coordination, pricing, and liquidity in decentralized physical infrastructure networks (DePIN), the PinFi protocol introduces a distinctive dynamic pricing mechanism. It enables providers to allocate excess computing resources to a "dissipative" PinFi liquidity pool, distinct from traditional DeFi liquidity pools, ensuring seamless access for clients at equitable, market-based prices. This approach significantly reduces the costs of accessing computing power, potentially to as low as 1% compared to existing services, while simultaneously enhancing security and dependability. The PinFi protocol is poised to transform the dynamics of supply and demand in computing power networks, setting a new standard for efficiency and accessibility

Self-Attention in Transformer Networks Explains Monkeys' Gaze Pattern in Pac-Man Game

We proactively direct our eyes and attention to collect information during problem solving and decision making. Understanding gaze patterns is crucial for gaining insights into the computation underlying the problem-solving process. However, there is a lack of interpretable models that can account for how the brain directs the eyes to collect information and utilize it, especially in the context of complex problem solving. In the current study, we analyzed the gaze patterns of two monkeys playing the Pac-Man game. We trained a transformer network to mimic the monkeys' gameplay and found its attention pattern captures the monkeys' eye movements. In addition, the prediction based on the transformer network's attention outperforms the human subjects' predictions. Importantly, we dissected the computation underlying the attention mechanism of the transformer network, revealing its layered structures reflecting a value-based attention component and a component that captures the interactions between Pac-Man and other game objects. Based on these findings, we built a condensed attention model that is not only as accurate as the transformer network but also fully interpretable. Our results highlight the potential of using transformer neural networks to model and understand the cognitive processes underlying complex problem solving in the brain, opening new avenues for investigating the neural basis of cognition

Bounds of Block Rewards in Honest PinFi Systems

PinFi is a class of novel protocols for decentralized pricing of dissipative assets, whose value naturally declines over time. Central to the protocol's functionality and its market efficiency is the role of liquidity providers (LPs). This study addresses critical stability and sustainability challenges within the protocol, namely: the propensity of LPs to prefer selling in external markets over participation in the protocol; a similar inclination towards selling within the PinFi system rather than contributing as LPs; and a scenario where LPs are disinclined to sell within the protocol. Employing a game-theoretic approach, we explore PinFi's mechanisms and its broader ramifications. Our findings reveal that, under a variety of common conditions and with an assumption of participant integrity, PinFi is capable of fostering a dynamic equilibrium among LPs, sellers, and buyers. This balance is maintained through a carefully calibrated range of block rewards for LPs, ensuring the protocol's long-term stability and utility

STUDY ON THE DRIVING GAZE SHIFT CHARACTERISTICS OF VISION INTERESTING AREA ON MOUNTAINOUS ROAD

Mountainous road landscape is the main source of driving information. The characteristics of two-lane mountainous road result in real-time dynamic changes in the driver's vision interesting areas. In order to explore the dynamic gaze characteristics, a driving experiment is conducted, and the gaze data of 10 drivers are collected. Markov chain is used to analyze the change process of gaze. The results show that: (1) when the current gaze point is in the straight front area, different road landscape has no significant impact on the gaze shift probability; (2) when the current gaze point is in the near left area, next gaze will expand the search scope to obtain much more driving information; (3) when the current gaze point is in the near right area, there is a high probability that the driver's next gaze will return to the front area; (4) when the current gaze point is in the far right area, the gaze will move back and forth between the near right and the far right areas; (5) when the current gaze point is in the far left area, there is a high probability that the gaze will remain in current area; (6) the main source of traffic information obtained by the driver in mountainous road landscape is the straight front area in the vision field, and the gaze point constantly shifts between the far ahead and the near ahead. The research results can provide technical reference for the construction of landscape in mountainous two-lane road

RESEARCH ON OPTIMIZATION OF MOTORWAY ROUTE DESIGN SCHEME IN MOUNTAIN AREAS BASED ON ENTROPY WEIGHT-TOPSIS MODEL

During the design process of a new mountainous motorways, multiple route schemes are often proposed for a comprehensive design effort. Each route scheme will have its advantages and disadvantages, so it is often difficult to choose a route scheme. Usually the expert decision method is used to screen the route schemes, but this method mainly relies on the personal experience of experts, and it is difficult to measure the criteria, which can lead to the embarrassing situation that different experts do not agree on the choice of routes.In order to optimize the route scheme for the design process of mountainous motorways and improve the efficiency and scientificity of route scheme selection, evaluation indicators were selected from traffic safety, construction economy, and environmental friendliness. The Entropy Weight Method (EWM) was used to assign the weight of the evaluation indicators. By improving the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), the problem of subjective opinions and excessive reliance on objective data by designers in the multi factor evaluation process was overcome. A EWM-TOPSIS evaluation model was proposed. By analyzing specific examples of mountainous motorway construction, research results were obtained. The results indicate that the model can reflect the designer\u27s intention towards the route scheme and the actual construction project. There is a high degree of consistency with the expert\u27s empirical judgment, which verifies the feasibility and accuracy of the model. This model can provide reliable reference and basis for the decision-making of motorway route schemes in mountainous areas